Linear Hydro-Kinetic Power Generation System

ABSTRACT

A linear hydro-kinetic power generation system generates electrical power from low head water, such as rivers or irrigation channels. The linear hydro-kinetic power generation system includes a paddle system configured to travel in a continuous loop when acted upon by the low-head water. The linear hydro-kinetic power generation system also includes a linear electric power generation subsystem configured to generate electricity as the paddles travel along the continuous loop.

CROSS REFERENCE TO A RELATED APPLICATION

This application claims benefit of and is based upon U.S. provisionalapplication No. 61/436.532 filed 26 Jan. 2011.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

Implementations of the present invention relate generally to thegeneration of power using flowing water.

2. Discussion of the Relevant Art

Hydropower is the production of electrical or mechanical power using theforce of falling or flowing water. Hydropower is one of the most widelyused forms of renewable energy. Often power is converted to electricityand distributed to users on an electrical grid. Advantages ofhydroelectric power include: no direct waste, no intermittency ofprovided power, no fuel costs, and considerably lower output levels ofpollutants and greenhouse gases like carbon dioxide (CO₂) than fossilfuel powered energy plants.

Traditionally large dams have been constructed in order to implementhydroelectric power. The dam serves to organize the flowing water andincrease the pressure or head for use in a hydroelectric turbine.Unfortunately, dams and associated reservoirs submerge land upstream ofthe dams. The submersion land can destroy biologically productiveriparian habitats like riverine valley forests, marshland, andgrasslands. The loss of land is compounded by habitat fragmentation.Further, large dams can become a hazard with the potential to inflicttremendous damage and loss of life should the dam ever fail.

Increasingly, nations are preventing the construction of new dams andseeking power capture in low head situations like canals, tidal flows,small dams, or natural river flows. In low head situations the pressureis low and power must be extracted from the natural velocity or kineticenergy of the water. Unlike with high head situations, the maximumpossible extractible power in low head situations is often too low tojustify costly turbine blades. Despite the need for systems that cangenerate power using low head situations, many attempts have provenimpractical or too costly.

BRIEF SUMMARY OF THE INVENTION

Implementations of the present invention provide systems, methods, andapparatus configured to convert kinetic energy of lower head flowingwater into power. In particular, one or more implementations of thepresent invention include a linear hydro-kinetic power generation systemincluding a linear electric power generation subsystem. Thehydro-kinetic power generation system includes paddles that drive thelinear electric power generation subsystem. Additionally,implementations of the present invention can be easily configured for avariety of installations.

Additional features and advantages of exemplary implementations of theinvention will be set forth in the description which follows, and inpart will be obvious from the description, or may be learned by thepractice of such exemplary implementations. The features and advantagesof such implementations may be realized and obtained by means of theinstruments and combinations particularly pointed out in the appendedclaims. These and other features will become more fully apparent fromthe following description and appended claims, or may be learned by thepractice of such exemplary implementations as set forth hereinafter.

The invention is a linear hydro-kinetic power generation systemconfigured to generate power using low-head flowing water. It comprisesmultiple of paddle subassemblies, a suspension mechanism for maintainingthe system stationary with respect to the moving water and at anappropriate depth, a conveyance system configured to route the paddlesin an elongated continuous loop, and a linear electric power generationsubsystem. The linear electric power generation subsystem may haveelectric coils and one or more magnets. The system is implemented suchtranslation of the paddle subassemblies along the conveyance systemcauses magnetic members to pass by electric coils, thereby inducingcurrent. The linear electric power generation subsystem may incorporateone or more rotary electric generator elements. The conveyance systemmay comprises a belt and one or more pulleys and the paddle blades maybe generally flat or curved. The paddle subassemblies may include apaddle blade manipulation mechanism configured such that the paddles arepositioned at a retracted angle during the return trip in the elongatedcontinuous loop. The paddle subassemblies may also include a paddle bladmanipulation mechanism that is actively driven in angle around one ormore axes such that the paddle blades may be oriented at anyadvantageous angle.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otheradvantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 illustrates a perspective view of an example linear hydro-kineticpower generation system;

FIG. 2 illustrates an end view of the example linear hydro-kinetic powergeneration system of FIG. 1;

FIG. 3 illustrates a perspective view of another example linearhydro-kinetic power generation system having an alternative suspensionmechanism;

FIG. 4 illustrates a side view of various components of the examplelinear hydro-kinetic power generation system of FIG. 1;

FIG. 5 illustrates a cross section view of various components of theexample linear hydro-kinetic power generation system of FIG. 1.

FIG. 6 illustrates an isometric view of another example linearhydro-kinetic power generation system having a two axis paddle blademanipulation mechanism being configured for combined wind and waterpower generation.

FIG. 7 illustrates an isometric view of an example linear electric powergeneration system demonstrating the principles of inductive powergeneration

FIG. 8 illustrates a cross section view of various components of anexample linear hydro-kinetic power generation system having wheels aspart of the conveyance subsystem.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention is directed toward systems, methods, and apparatusconfigured to convert kinetic energy of lower head flowing water intopower. In particular, one or more implementations of the presentinvention include a linear hydro-kinetic power generation systemincluding a linear electric power generation subsystem. Thehydro-kinetic power generation system includes paddles that drive thelinear electric power generation subsystem. Additionally,implementations of the present invention can be easily configured for avariety of installations.

For example, FIG. 1 is an isometric view of a linear hydro-kinetic powergeneration system 100 and FIG. 2 is an end view of the system. Thelinear hydro-kinetic power generation system 100 can be used to convertkinetic energy of the low-head flowing water into electric or mechanicalpower. One will appreciate in light of the disclosure herein that one ormore implementations of the linear hydro-kinetic power generation system100 can be low cost, yet effective for generating power using low-headflowing water.

As part of the linear hydro-kinetic power generation system 100, FIG. 1illustrates how the system can include a paddle assembly 102 forcapturing the kinetic energy of the water source. The linearhydro-kinetic power generation system 100 can also include a linearelectric power generation subsystem 104 for converting the kineticenergy captured by the paddle assembly 102 into electric power.Furthermore, the example linear hydro-kinetic power generation system100 can include a suspension mechanism 110 for ensuring that the linearhydro-kinetic power generation system 100 is maintained stationary inthe water at an appropriate depth.

For example, FIG. 2 illustrates that the suspension mechanism 110 cancomprise one or more floats 108 a, 108 b and one or more guy wires 106a, 106 b. The floats 108 a, 108 b can maintain the linear hydro-kineticpower generation system 100 in the water at an appropriate depth. Theguy wires 106 a and 106 b can be anchored to the bank, side wall, orbottom of the water way. The depth is to be set such that the linearelectric generation hardware is kept generally out of the water and notsubject to the corrosive and erosive effects of the flowing water. Thepaddles should still be fully submerged because any paddle material outof the water would not contribute to energy capture. The floats 108 a,108 b can comprise a polymer or other suitable material that allows thefloats to create sufficient buoyancy to support the linear hydro-kineticpower generation system 100. FIG. 3 shows an alternate embodiment wherestructural supports 132 are attached to one or both watercourse banksand cantilevered out to an appropriate housing for the linear electricgenerator. Yet another embodiment might use moorings or anchors from thebase of the channel to place the system. The adaptability of systemplacement is an advantage of the invention.

Referring now to FIG. 2 the paddle assembly 102 will be described ingreater detail. The paddle assembly 102 can comprise a plurality ofpaddle subassemblies 111—see also FIG. 4 for a side view. Each paddlesubassembly 111 can comprise a generally flat portion 105 which will becalled the blade or paddle blade that captures the kinetic energy of thewater and a paddle handle 107. The paddle handle 107 attaches to or isan integral piece with the blade 105 on one end and connects to thepaddle manipulation mechanism 118 on the other end in a manner that willbe described in detail for example embodiments later. The blade can begenerally flat to minimize cost of materials and cost of forming. Curvedor cupped blades to create more drag in the water can also be a part ofthe design. The size of the blade varies with the size of the flowingwatercourse and amount of energy that will be extracted. For smallstream and canal flows, the width and height of the blade may be from 15to 150 cm. The thickness may be from 0.2 to approximately 1 cm for suchflows. For large low head river flows and tidal driven flows the limitswill be driven by practical handling concerns and not the size of theflow. The width and height of the blades for these may range from 140 cmto the 100 m range especially since multiple paddle blade portions maybe welded or fastened together. In the example embodiment depicted inFIG. 2, the paddle handles 107 should be only long enough so that thetop of the paddles is about 5-20 cm below the water surface. Anobjective is to create cost effective paddles that can be spaced over along length of flowing water. This increases the energy available forcapture (without requiring dams or civil engineering works). Thereforethe paddle subassemblies should be made of low cost materials and formedby low cost forming methods. Materials may include polymers, corrosionresistant steels, brass or others. Forming methods include stamping,molding, casting, punching, extruding, welding or combinations thereof.

Referring to FIG. 4 for an example embodiment, the paddle subassemblies111 are secured to a conveyance system 113 via the paddle manipulationmechanisms 118. The conveyance system 113 can comprise a belt 112 andpulleys 114. In the example the pulleys are located at the ends of thehydrokinetic system, but the system may be designed with pulleys at theends, in the middle or otherwise interspersed along the length asrequired to promote a smooth, accurate motion of the paddlesubassemblies 111. The belt 112 and pulleys 114 can allow the paddlesubassemblies 111 to follow an elongated continuous loop. The belt canbe made of rubber, polymers, metallic elements or some combinationthereof. For example a rubber belt with wire or foil reinforcingmetallic material can result in a strong but pliable belt for smoothconveyance. The pulley radii are sized to move the combination of thebelt and paddle manipulation parts accurately along the length of thesystem. The pulleys 114 are attached to a long channeled structuralmember 115 via axles 117 by a pinned or captured method.

Via the conveyance system 113, the flowing water (indicated by arrow116) can cause the paddle subassemblies 111 of the paddle assembly 102to move along the length of the linear hydro-kinetic power generationsystem. The belt 112 and end pulleys 114 return the paddles along thetop of the linear hydro-kinetic power generation system to an originpoint of the cycle. Thus, the paddles subassemblies 111 can follow anelongated linear like continuous loop. The belt 112 and pulleys 114 canconvey the paddle subassemblies 111 efficiently at a minimum cost andfrictional loss to the linear hydro-kinetic power generation system 100.Referring to FIG. 1, the paddle subassembly and conveyance mechanismsdescribed in the example embodiment allow movement within the paddleassembly 102 along the length of the linear hydro-kinetic powergeneration system which can activate the linear electric powergeneration subsystem 104 to generate power. In alternate embodiments oneor more rotary electric power generation units 105 can be incorporatedin the elongated linear hydro-kinetic power generation system. These canbe in addition to or in place of the linear electric generator subsystem104. For example rotary electric generators could be attached by a shaft103 to axles of the pulleys 114 that are described as part of theexample conveyance system.

One will appreciate in light of the disclosure herein that theconfiguration of the paddle assembly 102 can provide a number ofadvantages. For example, in contrast to other linear electric powergeneration systems which run on reciprocating linear motion, the linearhydro-kinetic power generation system is continuous. Thus, there is noenergy loss due to the stopping and restarting associated with areciprocating linear motion. Furthermore, in contrast to non-elongatedrotary wheel hydro power capturing systems, embodiments of the linearhydro-kinetic power generation system can be configured such that atleast about half of all of the paddle subassemblies 111 are alwaysactively capturing power from the water source.

Additionally, the relatively long run of the linear hydro-kinetic powergeneration system 100 can allow for efficient capture of power from thelow-head flowing water. The linear hydro-kinetic power generation system100 shown in FIGS. 1 and 4 includes six paddle subassemblies 111. Inalternative implementations, the number of paddle subassemblies 111 canbe increased or reduced to maximize the efficiency of the linearhydro-kinetic power generation system 100. Additionally, various runs ofpaddle subassemblies 111 can be connected together to span the width ofa water source to further maximize the efficiency of power captured fromthe water source.

In most hydro-power generation configurations, it is a goal for 100% ofthe available water to be routed through the power generation area(usually a turbine) because this maximizes output power. For the linearhydro-kinetic system 100, this is not the case and the explanation willgive further methodology for sizing the paddles and linear generator. Ifa paddle blade blocked the entire channel, there would be no way for thewater to also flow and thereby provide an opportunity for energycapture. In a channel flow the blockage ratio may be defined as theratio of the cross sectional area of the structure in the flow to thecross sectional area of the flow. For the linear hydro-kinetic systemthe blockage ratio should stay in the range of 40-80%. For largewatercourses where for some reason it was not desired or practical touse larger systems the blockage ratio could go lower than 40%, forexample from 1%-40%. With the blockage ratio in these ranges some energyis kept by the water flowing faster than and around the paddles—but thisis necessary for the flow not to back up behind the structure andoverflow its banks. The energy may be exchanged in the water furtherdownstream and captured in part by a more downstream paddle. Whetherdesigning one paddle assembly or configuring for multiple linearhydro-kinetic systems to be deployed in a single water way, the blockageratio ranges provide guidelines to help determine paddle blade geometry.Another advantage of not exceeding 80% blockage ratio is that fish arefreer to move around the structure. Because of the openness of thesystem and large water space between paddle blades the linearhydro-kinetic system 100 is expected to be fish friendlier than otherhydraulic options.

Referring now to FIG. 5, a cross section view of various components ofthe example linear hydro-kinetic power generation system 100 is shown.FIG. 5 illustrates that in the example, the paddle blade manipulationmechanism 118(a or b) can comprise an axle 119, a base 124, a torsionspring 120, and one or more stops 121. The paddle blade manipulationmechanism 118 governs the angle of attack for the paddle blades. In theexample it can orient the paddle blades essentially normal to the flowor at any angle to the flow while the blades are in the water andcapturing power. When the blades are out of the water and returning toan origin via the conveyance system, the paddle blade manipulationmechanism 118 can bias the blades to lay nearly flat. By having theblades 105 lay nearly flat during the return trip across the top of thelinear hydro-kinetic power generation system 100, drag forces throughthe air are minimized.

The lower portion of FIG. 5 illustrates that the paddle handles 107 canbe secured to the manipulation mechanism with a pinned axle through thepaddle handle—or captured bearing assemblies can be press fit into thepaddle handle. Indeed many mechanical methods could be used as long as arotational movement of the paddle assemblies around an axisperpendicular to the flow direction is permitted. The axle or rotatingbearing may be made of steel or other structural materials.

The paddle manipulation mechanism 118 has a base 124 that is attached tothe belt of the conveyance system 112—not shown in FIG. 5, but an areafor attaching is identified by arrow 123. In the example, the base 124can be attached to the belt by bolting, riveting, a press or crimp fitor others and may be made of steel, aluminum, bronze, polymers or othersuitable materials. The base 124 is attached to an electric powergeneration member that will be described in detail later. For examplethe base and electric power generation member may be a one piececonstruction that has a T-shaped protrusion, or multiple pieces may bebolted or otherwise fastened together. The torsion spring 120 can biasthe blades 105 to a very low angle when there is little or no waterforce on the blade 110. For the example in FIG. 5, one end of thetorsion spring 120 fits into a cavity in the rotating member (part ofthe paddle handle 107), the other end of the torsion spring is held inplace in a cavity on the base 124 side. In the example the axle 119passes through the middle of the torsion spring 120. Thus the torsionspring 120 exerts a biasing force that in the absence of water pressurewill force the paddle blades to a flat position. The torsion springforce is sized in proportion to the relative water velocity squared(relative water velocity equals average water velocity minus paddlevelocity) and the area of the paddle. For example, for a 2.3 m̂2 paddlearea and a relative velocity of 0.5 m/s, the torsion spring may have aforce of 20-50 Newtons. For larger or smaller systems with larger orsmaller paddle areas and water velocities, the torsion springs may havedifferent ranges such as from 0-25 Newtons, from 50-150 Newtons or from140 Newtons to more than 2000 Newtons. A torsion spring having asuitable combination of force and spring length can be selected frommanufacturer's catalogs for such springs and this will fix all springdimensions. When a paddle blade 105 enters the water, the momentum forceof the flowing water can overcome the biasing force created by thetorsion spring 120. Thus, the momentum force of the flowing water canforce the paddle blade 105 to a fixed position corresponding toapproximately 90 degrees relative to the water flow (see FIG. 4). Thetorsion spring may be made of spring steel or suitable spring materials.

Referring to the upper portion of FIG. 5, to ensure that the blades 105can be properly oriented, the exemplary paddle blade manipulationmechanism 118 includes a stop or stops 121 configured to restrict thepaddle handle 107 or paddle blade 105 from over or under rotating. Thestops are formed protrusions from the base 124 and/or the paddle handles107 that impede motion and confine the range of angular motion, forexample from 0 degrees to 90 degrees. In the example, 0 degreesrepresents paddle blades laid flat and 90 degrees represents paddleblades normal to the flow of water. The stops can be configured for anypractical range of angles such as from 1-5 degrees to 90-120 degrees or0-360 degrees. The low part count and simplicity of the exemplary paddleblade manipulation mechanism 118 can provide a cost effective solution.

In alternative implementations, the paddle subassemblies 111 may notinclude a paddle blade manipulation mechanism 118 or there may be a moresophisticated mechanism. For example FIG. 6 refers to situations inwhich wind indicated by arrow 140 would be favorable to overcomingfrictional losses and generating power during the paddle return trip. Inthis example, a wind sensor 142 could detect wind direction andcommunicate with so as to govern one or more active actuators 144 suchas a servo motor driven rotary positioner. This allows two-axisactuation (one axis indicated by arrow 139 that is parallel to thepulley axle and one twisting angle axis indicated by arrow 138). If thesensor indicates favorable wind, the paddle blades 105 can then bepositioned to remain upright and act as sails to capture power from thewind. Thus, in one or more implementations the linear hydro-kineticpower generation system 100 can take advantage of favorable wind as acombined wind/water kinetic power capture device.

FIG. 7 illustrates an example depicting the principle of electricalpower generation for the linear electric power generation subsystem 104from FIG. 1. The linear hydro-kinetic generation system is not limitedto linear generation elements only and can incorporate standard rotarymotion electric generators such as connected to the pulley axles. FIG. 7represents a somewhat inverted view relative to other figures in thatthe paddle subassemblies 111 would be above rather than below the moveryoke designated 152 as indicated. In this example, a linear electricgenerator can comprise one or more mover yokes 152, a stator yoke 150,and one or more coils 154. In the example the mover yoke 152 comprises astructure including permanent magnets or electromagnets such that thereare two or more magnetic poles (158 a though 158 d) acting in the mover.The stator yoke 150 comprises a slotted structure that can accommodatethe coils 154. The coils can be made of an electrically conductivematerial such as copper wire or other conducting wire or laminateconducting material. Per Faraday's law of induction, when the mover yoke152 translates with respect to the stator yoke 150 and coils 154, acurrent is induced in the coils. The translation direction is indicatedby arrow 156. In the example, as the magnetic flux associated with thealternate north and south poles of the mover yoke 152 cut across thecoils 154, a natural commutation creating an alternating current isrealized. The coils may be electrically connected together in variousarrangements including series, parallel, or combinations of series andparallel. One will appreciate that many configurations are possible suchas slotted or slotless stator yokes, excited electromagnets either onthe mover yoke, stator yoke or both; and various configurations ofelectrical power phases. There are also multiple options for commutationto achieve direct current (DC) or one or more phase alternating current(AC) electrical output. The linear hydro-kinetic power generation system100 in FIG. 1 may incorporate any of these configurations for use in thelinear electric generation subsystem 104 and references are includedherein describing a variety of these configurations.

Referring again to FIG. 5, one finds a cross section, view which furtherillustrates details of the exemplary linear electric power generationsubsystem 104. In particular, the linear electric power generationsubsystem 104 can include a channeled stator yoke 122 and a slide member124. The channeled stator yoke 122 may be formed to incorporate slots towhich electrical conductor coils 125 are wound. It also serves to couplethe magnetic flux into the electrical conductor coil sets. The channeledstator yoke may be made of ferrous steel, iron, non-ferrous material orother materials. The channeled stator yoke 122 can extend substantiallythe length of the linear hydro-kinetic power generation system 100between the pulleys 114 (FIG. 3). The slide member 124 can be sized andconfigured to fit within a slot of the channeled stator yoke 122. As anexample of a slot configuration, the channeled stator yoke 122 caninclude a T-shaped slot, and the slide member 124 can include a T-shapedprotrusion. A T-shaped slot may be advantageous in that it can beconfigured so that multiple parts of the magnetic flux paths from apermanent magnet mover similar to the one depicted in FIG. 7 (152), cutacross multiple coils 125 (4 sets of coils in the example). Thispromotes high power generation in a comparatively smaller generator.

In one implementation, electric coils can be positioned in arms 126 ofthe channeled stator yoke 122 and extend along the length of thechanneled stator yoke 122. In other embodiments the channel could haveother shapes without arms or there could be no channel. Inimplementations, the protrusion of the slide member 124 can include oneor more permanent magnets or can include switched reluctanceelectromagnets. The permanent magnets can be made of materials such asrare earth magnets, neodymium diboride, aluminum nickel cobalt, orothers. It can be made as a multi-part composite material having piecesof permanent magnet material combined with other materials such aspolymers. Thus, water acting on the paddle subassemblies 111 can causean attached slide member 124 to translate along the channeled statoryoke 122. As the magnetic mover yokes 152 attached to each paddle moveacross the coils 154 positioned in the channeled stator yoke 122,current is induced in the coils and electricity is generated. Thegenerated electricity can then be collected, stored, and distributedusing a power harness connected to the linear hydro-kinetic powergeneration system 100.

In alternative implementations, the slide members 124 can include coilsand the channeled stator yoke 122 can include magnets. In thisimplementation the electricity capturing coils are the moving membersmaking the collection and redistribution difficult, probably requiringcommutators such as brushes or contactors. In yet anotherimplementation, one can use commutators or an inductive excitation tocreate a leading or lagging magnetic field in the slide members—thusavoiding the need for permanent magnets. This class of electromagneticgenerators may be known as self-excited or switched reluctance machinesand linear varieties are taught in U.S. Pat. No. 4,369,383 to LawrenceLangley 1983, which is hereby incorporated by reference herein. Linearelectric generators can also be configured to generate direct current(DC) electric power or single or multiple phase alternating current (AC)outputs as disclosed in Boldea and Nasar, “Permanent-Magnet LinearAlternators Part 1: Fundamental Equations” IEEE TRANSACTIONS ONAEROSPACE AND ELECTRONIC SYSTEMS, Vol. AES-23, No. 1, pp. 73-78, 1986.Thus, one will appreciate that the linear electric power generationsubsystem 104 can be constructed in a variety of different ways. Thus,the present invention is not limited to any depicted implementation.

The electromagnetic force that is resistive to motion governs how muchelectricity will be generated in the linear electric generator. The coilsizes, magnetic structure sizes and selection and dimensions of thelinear generator can be derived knowing this force according to Trumper,Kim, and Williams, “Design and analysis framework for linearpermanent-magnet machines,” Industry Applications, IEEE Transactions on,vol.32, no.2, pp. 371-379, March/April 1996. The total force adding thisresistive force and the frictional loss forces is to be sized such thatthe paddle velocity is expected to be between about one third and onehalf of the water velocity for maximum power generation. The frictionalloss forces would be expected to be much smaller than theelectromagnetic forces and may be estimated to a first order usingNewton's equations for friction. For example, the force of frictionequals the product of any force orthogonal to the direction of motionand a coefficient of static friction μs that can be estimated given thematerials chosen. As such, a formulation for sizing the system dependingon the flow parameters (water velocity and sizes of the flow channel)has been disclosed herein.

Thus in an example embodiment depicted in FIG. 5, when a paddlesubassembly 111 is in the water, the slide member 124 can travel alongthe channeled stator yoke 122. On the return trip the slide member 124can travel along a guide 128. The pulley 114, belt 112, and slide member124 can be designed with a small mechanical clearance so that after apaddle assembly turns into the water around a pulley 114, the T-shapedprotrusion of the slide member 124 will clear and be guided down theslot in the channeled stator yoke 122. As shown, the guide 128 can eachinclude a groove 130 allowing it to accommodate the motion whilemaintaining slide member coupling to the belt 112 (see FIG. 5).

In one or more alternate implementations as depicted in FIG. 8, thelinear hydro-kinetic power generation system 100 may not include a guidemember 128. In its place the linear hydro-kinetic power generationsystem 100 can include an additional channeled stator yoke 122 b. Insuch implementations the magnets of the moving members 124 a, 124 b caninduce current in coil sets 125 a-d in the lower channeled stator yoke122 a on one leg of the continuous cycle, and current in coil sets 125e-h in an upper channeled stator yoke 122 b during the return trip. FIG.8 also depicts an alternate implementation to avoid sliding members. Inthis implementation all protrusion and slots have ample clearance. Themoving members are guided by brackets 160 to which are applied axles 162and around which turn wheels 164. Wheeled configurations may beadvantageous for reducing frictional resistance to the linear motion.

Table 1 summarizes the parts and computed expected performance forassemble-able exemplary power generation systems.

TABLE 1 Design Element Value Length 50 m-100 m Output power 40-100 kWCanal bottom slope 1 m-3 m per 350 m length Elevation drop over system.5-1.1 m Flow width 1-4.5 m Typical flow depth 1-3 m Number of paddlesubassemblies 8-24 Paddle blade width About 3 m Paddle blade heightAbout 1.9 m Blockage ratio About 63% Structural member square About .1 mcross section Structural member thickness About 2.5 mm Torsion springforce 100-250 Newtons Suitable Torsion spring TS1100-90-182115-R fromMSD part number spring Stop angles 3° and 90° Stator yoke cross sectionAbout .1 by .077 m dimensions Stator yoke material Ferrous steel Moveryoke - T protrusion Material: Aluminum nickel cobalt permanent magnetwith Teflon coating Linear electric generator Single phase synchronousAC configuration Coils Stranded AWG 4 gauge copper wire Wiring of coilsseries Operating voltage, current 240-440 Volts, 50-200 amps Harness togrid type S.O. 2-4 gauge cord - with conduit and supported/routed via acantilever arm Anchoring method Cantilever arms - welded stainless steeltubing Grid interface 113430-000-00 AC/DC rectifier from Caseyequipment, GT100-480 DC grid tie inverter from Xantrex

The invention is advantageous relative to many other approaches becauseit can be scaled up or down easily by adjusting the paddle sizes andlength of the system. Therefore the potential embodiments and range ofuse can be broad. One good example of use for the invention is powergeneration in a tranquil irrigation canal. Such canals are common andcurrently hydropower is not extracted from them due to the low headnature of the structures. However, their use for human irrigationpurposes implies good access, usually straight runs and wellcharacterized velocities for optimizing designs. Typically it would bereasonable to assume there are electrical grid resources nearby thesecanals. The invention is floated in the canal per FIG. 1 or hard mountedto the canal embankment per FIG. 5.

In embodiments, the output power can be routed to a use site i.e. anelectrical load or grid interface point (see FIG. 3). This routing is tobe accomplished by an electric conductor harness 134 running from thesystem 100 to the load or grid interface point 136. The harness can berouted along or within cantilever supports or guy wires in exampleembodiments or a protective conduit can be made for the purpose ofharness routing. Harness wire size and type and conduit choices can bederived from governmental electric codes such as the United StatesNational Electric Code (NEC).

In embodiments requiring an interface to the electrical grid, severalchoices are suitable. The functional objective is to supply power ofgrid quality in terms of voltage and phase and to include fail safessuch that the power can be disconnected from the grid in the event of afault. One alternative is an electronic load governor, such as arecurrently employed in various hydropower installations. Anotheralternative would be to configure the linear electric generator for DCoutput or to use a rectifier and then add a grid tie inverter. Theoptions may be implemented with or without the use of electrical energystorage. Schematically in FIG. 3, box 136 represents a grid interfaceelectronics assembly. This assembly can comprise any of the embodimentslisted herein by which electrical power can be sourced to the grid or aload or it may comprise any other such interface to a load or grid suchas are commercially available.

The simplicity of installation and flexibility of deployment of theinvention are major features.

The present invention may thus be embodied in other specific formswithout departing from its spirit or essential characteristics. Thedescribed embodiments are to be considered in all respects only asillustrative and not restrictive. The scope of the invention is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes that come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

I claim:
 1. A linear hydro-kinetic power generation system configured togenerate power using low-head flowing water, comprising: a plurality ofpaddle subassemblies; a suspension mechanism for maintaining the systemstationary with respect to the moving water and at an appropriate depth;a conveyance system configured to route the paddles in an elongatedcontinuous loop; and a linear electric power generation subsystem. 2.The linear hydro-kinetic power generation system of claim 1 wherein thelinear electric power generation subsystem includes one or more electriccoils and one or more magnets, wherein translation of the plurality ofpaddles along the conveyance system causes magnetic members to pass byelectric coils, thereby inducing current. The linear electric powergeneration subsystem comprises from zero to multiple rotary electricgeneration elements in combination with one or more linear electricgenerator.
 3. The linear hydro-kinetic power generation system of claim1 wherein the linear electric power generation subsystem includes one ormore electric coils and one or more magnets, wherein translation of theplurality of paddles along the conveyance system causes magnetic membersto pass by electric coils, thereby inducing current.
 4. The linearhydro-kinetic power generation system as recited in claim 1, wherein theconveyance system comprises a belt and one or more pulleys.
 5. Thelinear hydro-kinetic power generation system as recited in claim 1,wherein each paddle blade has a generally flat shape or a curved shapeallowing for curvature in two dimensions up to and including hollowhemispherically shaped paddle blades.
 6. The linear hydro-kinetic powergeneration system as recited in claim 1, wherein the suspensionmechanism comprises one or more floats and one or more guy wires.
 7. Thelinear hydro-kinetic power generation system as recited in claim 1,wherein the suspension mechanism comprises anchoring structures affixedto the water course bank, sides or bottom.
 8. The linear hydro-kineticpower generation system as recited in claim 1, the paddle subassembliescomprise a paddle blade and paddle handle that are attached to theconveyance system.
 9. The linear hydro-kinetic power generation systemas recited in claim 1 further comprising: a paddle blade manipulationmechanism configured to bias the paddles into a retracted positionduring a return trip along the conveyance system.
 10. The powergeneration system as recited in claim 9, wherein the paddle blademanipulation mechanism comprises a torsion spring or an actively drivenactuator in one or more axes of rotation.
 11. A method for operating alinear hydro-kinetic power comprising: placing the system in a watercourse, fixing the position of the system relative to the water usingthe suspension system, and capturing electrical power from the flowingwater using the paddle subassemblies to activate the linear electricgeneration subsystem transmitting the captured electrical power to auseful load near by the system.
 12. The method for operating a linearhydro-kinetic power as recited in claim 11, wherein the transmission ofcaptured electrical power includes interfacing the power to theelectrical utility grid.
 13. A method for designing a linearhydro-kinetic power system comprising: estimating a size for the paddleblades relative to the water way cross section, determining appropriateresistance force for the electrical generation elements, and sizing theremaining components of the system for efficient operation.
 14. Themethod for designing a linear hydro-kinetic power system as recited inclaim 13 wherein the determination of the appropriate electromotiveresistance force is based upon maintaining the paddle blade speedthrough the water at approximately one third to one half of the averagewater speed.